https://git.reactos.org/?p=reactos.git;a=commitdiff;h=6d441f7d65f57c0f5b6da59ae851640a6e787875
commit 6d441f7d65f57c0f5b6da59ae851640a6e787875 Author: Stanislav Motylkov <[email protected]> AuthorDate: Tue May 25 20:32:42 2021 +0300 Commit: Stanislav Motylkov <[email protected]> CommitDate: Tue Jun 22 02:42:04 2021 +0300 [XBOX][FREELDR] Initialize PCI-AGP bridge BAR values This fixes problem with Xbox GPU not being detected as a children device. CORE-17600 CORE-16216 --- boot/freeldr/freeldr/arch/i386/xbox/xboxmem.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/boot/freeldr/freeldr/arch/i386/xbox/xboxmem.c b/boot/freeldr/freeldr/arch/i386/xbox/xboxmem.c index eb7ce22c232..14f700e7751 100644 --- a/boot/freeldr/freeldr/arch/i386/xbox/xboxmem.c +++ b/boot/freeldr/freeldr/arch/i386/xbox/xboxmem.c @@ -86,6 +86,31 @@ XboxInitializePCI(VOID) PciData |= 0x00020200; WRITE_PORT_ULONG((PULONG)PCI_TYPE1_DATA_PORT, PciData); } + + /* Select AGP to PCI bridge */ + PciCfg1.u.bits.DeviceNumber = 30; + /* Select register VendorID & DeviceID */ + PciCfg1.u.bits.RegisterNumber = 0x00; + + WRITE_PORT_ULONG(PCI_TYPE1_ADDRESS_PORT, PciCfg1.u.AsULONG); + PciData = READ_PORT_ULONG((PULONG)PCI_TYPE1_DATA_PORT); + + if (PciData == 0x01B710DE) + { + /* Zero out uninitialized AGP Host bridge BARs */ + + /* Select register BAR0 */ + PciCfg1.u.bits.RegisterNumber = 0x10; + WRITE_PORT_ULONG(PCI_TYPE1_ADDRESS_PORT, PciCfg1.u.AsULONG); + /* Zero it out */ + WRITE_PORT_ULONG((PULONG)PCI_TYPE1_DATA_PORT, 0); + + /* Select register BAR1 */ + PciCfg1.u.bits.RegisterNumber = 0x14; + WRITE_PORT_ULONG(PCI_TYPE1_ADDRESS_PORT, PciCfg1.u.AsULONG); + /* Zero it out */ + WRITE_PORT_ULONG((PULONG)PCI_TYPE1_DATA_PORT, 0); + } } VOID
